Aristoxenus of Tarentum was a Greek Peripatetic philosopher, and a pupil of Aristotle. He was the most famous music theorist in antiquity and came to be referred to simply as "the musician."

Most of his writings, which dealt with philosophy, ethics and music, have been lost, but one musical treatise, Elements of Harmony survives incomplete, as well as some fragments concerning rhythm and meter. The Elements is the chief source of our knowledge of ancient Greek music.